The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
An internal combustion engine used as a main power source of a vehicle is a discharge source of carbon dioxide and various pollutants, and has a significant influence on air pollution of residence and activity spaces of persons.
Therefore, regulation for emission gas of a land transport means such as the vehicle has been gradually strengthened. As a result, research into and development of a transport means that may use a power source other than a fossil fuel have been actively conducted.
One power source that may be a substitute for fossil fuel, which is a main factor of generation of carbon dioxide, is electrical energy, and a transport means driven by electricity does not generate pollution and generates a small amount of noise.
A battery used as a power source in the electric vehicle as described above should be repeatedly rapidly charged, movement of the transport means is limited at the time of charging the battery, and as the number of times of charging is increased, performance of the battery is rapidly deteriorated and a lifespan of the battery is rapidly shortened.
A device that may simultaneously solve disadvantages of a secondary battery as the power source for a transport as described above and a pollution problem of the internal combustion engine is a fuel cell. A fuel cell does not need to be charged like a secondary battery, may solve various problems due to direct combustion of the fossil fuel, does not substantially generate pollution, and may directly generate electricity.
However, in the case of the fuel cell, an output voltage is rapidly decreased in a high speed driving region in which a high voltage is required, such that the fuel cell does not supply sufficient electricity required for a driving motor. Therefore, there is a limitation in using the fuel cell as a power source of the electric vehicle.